Discovery doesn't wait. Neither do we.

Most of what we know about how a body's organs coordinate comes from looking at one system at a time — record the brain, then separately study the gut, then the heart, and try to stitch the story back together afterward. A new technique out of HHMI's Janelia Research Campus skips the stitching. Developed by postdoctoral researcher Virginie Ruetten in Misha Ahrens's lab and published this week in Nature, the method, called WHOLISTIC, records real-time activity from nearly every cell in a living vertebrate at the same time — nervous system, digestive system, and cardiovascular system, all captured together as they actually happen, not reconstructed afterward from separate experiments.

The trick is tracking calcium signals, which is essentially the shared language cells across the body use to communicate with their neighbors. The Ahrens Lab spent more than a decade building tools to image those signals across an entire zebrafish brain — genuinely difficult work on its own. WHOLISTIC takes that same foundation and extends it past the brain to the whole organism, combining high-speed volumetric fluorescence imaging with computational tools built to track and line up signals across completely different tissue types at once. That last part is the harder engineering problem than it sounds: a heart cell and a gut cell and a neuron don't behave the same way or sit still the same way, and getting a single system to follow all of them simultaneously, in a living animal, is most of what took years to build.

The findings that have already come out of it are the kind you don't get by studying one organ in isolation. The team found the brainstem is what redirects blood flow away from the gut and toward the brain and muscles when oxygen runs low — a whole-body decision that only shows up if you're watching the whole body. They also caught traveling waves of activity moving along the spinal cord, coming from cells called ependymal cells, specifically during quiet periods with no motor activity — a pattern that looks like it could be tied to sleep, though that's still an open thread rather than a settled answer. Separately, they found that ketamine doesn't just act on neurons the way it's usually described — it also activates the meninges, the membranes wrapping the brain and spinal cord. And cartilage cells, of all things, turned out to respond directly to cold. None of these were the headline result WHOLISTIC set out to prove; they're the kind of finding you only stumble into when you're recording everything at once instead of testing one hypothesis at a time.

The scope, for now, is a larval zebrafish — small and naturally transparent, which is exactly what makes this kind of whole-body optical recording possible in the first place. The team, working with collaborators at University College London, Virginia Tech, and Tsinghua University, is already adapting the approach for Danionella, a fish that stays transparent into adulthood, which would open the door to studying more complex, adult-level behavior with the same whole-body view. It's also worth noting what this isn't yet: a tool for mammals, or humans, whose bodies aren't optically transparent in the same way. What makes WHOLISTIC likely to spread quickly through other labs regardless is that it doesn't require exotic hardware — the microscope involved is a common type many biology labs already have, and the computational side of the method is open source. The ambition behind it is bigger than one fish: understanding a nervous system by only ever measuring the brain, when the body clearly makes plenty of its own decisions outside it, may have always been missing more than researchers realized.

For years, ruthenium dioxide was the answer to a question physicists thought they'd already closed. It was one of the first materials proposed as a candidate for altermagnetism — a third form of magnetism, distinct from the two classical types everyone learns in school, first theorized back in 2019 and only experimentally confirmed in other materials in 2024. But every time researchers actually tested bulk ruthenium dioxide, the ordinary, naturally grown form of the material, they found nothing. No magnetic signal. The field settled into a rare moment of consensus: this material simply isn't magnetic. A new study out of Rice University, led by physicist Ming Yi with collaborators at the University of Minnesota and the Paul Scherrer Institute, just complicated that settled answer.

The trick was changing the material's shape, not its chemistry. The team, with Rice graduate Yichen Zhang as first author, grew ruthenium dioxide into an ultrathin film only a few atomic layers thick, then placed it under lattice strain — essentially stretching or compressing its atomic structure by growing it on a surface it doesn't naturally match. To see what that strain actually did to the electrons, they used a technique called spin-resolved angle-resolved photoemission spectroscopy, which maps out spin texture: the way a material's electron magnetic moments are arranged in space, and the clearest signature of what kind of magnetism, if any, is actually present. Under strain, the ultrathin film showed spin patterns consistent with altermagnetism. Remove the strain, or go back to the bulk form of the same material, and that signature disappears.

That's the part worth sitting with: same chemical formula, same element, same crystal — and completely different magnetic behavior depending on how thin it's made and how hard its atomic lattice is being pushed. It suggests the strain itself isn't incidental to the effect, it's the switch. If that holds up under further study, strain becomes a genuine tuning knob, a way to deliberately turn this kind of magnetism on or off, or dial it up and down, in an engineered material rather than hoping to find it naturally occurring somewhere.

That tuning knob is the reason this matters beyond resolving an old academic debate. Altermagnetism is of real interest for spintronics — a way of building computer memory and processors around electron spin rather than just electrical charge, with the promise of devices that are smaller, faster, and more power-efficient than what's used today. A controllable way to induce that behavior in an otherwise unremarkable, well-understood material would be a genuinely useful tool for that field, not just a curiosity. None of that is built yet — this is a fundamental physics result, carefully measured in a lab, not a working memory chip. But it's the kind of finding that tends to quietly become a starting ingredient a few years down the line, and it's a reminder that "we already know this material's properties" is a more fragile claim than it sounds, once someone changes the shape of the question.